Biomechanical evaluation of intramedullary nail versus tension band fixation for transverse olecranon fractures

OBJECTIVES: To compare the biomechanical stability of an alternative custom-designed intramedullary nail (IMN) fixation with that of traditional tension band wiring (TBW), the gold standard for stabilizing transverse olecranon fractures. DESIGN: Ex vivo biomechanical study. SETTING: Biomechanical laboratory. MATERIALS: Six pairs of elderly cadaver elbows. INTERVENTION: A simulated transverse olecranon fracture was created in each elbow after it had been denuded of most of its soft tissue. The right and left olecranons of each pair were alternately assigned to the IMN or TBW group. A tensile force was applied via the triceps tendon while the elbow was secured in 90 degree of flexion. MAIN OUTCOME MEASUREMENTS: Displacement at the simulated fracture segment was measured optically. Fixation failure was defined as >2 mm of fracture displacement. The differences in stiffness and maximum load to failure between the two treatments were analyzed for significance (P < 0.05) using a one-tailed paired t test. RESULTS: IMN fixation was significantly stiffer and stronger than TBW fixation. CONCLUSIONS: The locked IMN provided stronger and stiffer fixation than did TBW. Theoretically the IMN fixation would require less surgical exposure and would be expected to require fewer revisions than TBW fixation. IMN fixation warrants consideration as a clinical alternative to TBW.     

Biomechanical comparison of tension band suture fixation and tension band wiring in olecranon fractures

PurposeTraditional tension band wire fixation (TBWF) of olecranon fractures is associated with high revision rates due to implant-related complications. The purpose of the study was to compare the strength of fixation in olecranon fractures between TBWF and an all-suture based technique.MethodsA transverse fracture was created in 20 paired fresh-frozen human cadaveric elbows. Fractures were randomly (alternating right-left) assigned for fixation with either tension band suture fixation (TBSF) or TBWF. The elbow was fixed in 90° of flexion and underwent cycling loading by pulling the triceps tendon to 300 N for 200 cycles. Fracture displacement was optically recorded using digital image correlation (DIC). Finally, load-to-failure was assessed by a monotonic pull to 1000 N and failure mechanism was recorded.ResultsTwo specimens in the TBSF group were excluded from the cycling loading analysis due to technical difficulties with the DIC. After cyclic loading, median (min-max) fracture displacement was 0.28 mm (0.10–0.44) in the TBSF group and 0.18 mm (0.00–1.48) in the TBWF group (p = 0.315). No difference was found between the two groups in the repeated measures analysis of variance (p = 0.329). In the load-to-failure test, 6/10 specimens failed in the TBSF group (median load-to-failure 791 N) vs. 8/10 in the TBWF group (median load-to-failure 747 N). The TBSF constructs failed due to fracture of the dorsal cortex, suture breakage or triceps failure. The TBWF constructs failed due to breakage of the wire.ConclusionThere was no difference in fixation strength between the TBWF and TBSF constructs. Our findings suggest TBSF to be a feasible alternative to TBWF and we hypothesize that a non-metallic implant may have fewer implant-related complications.Level of evidenceBasic science study     

可吸收张力带固定尺骨鹰嘴骨折

[目的]介绍可吸收螺钉和可吸收线组成可吸收张力带固定尺骨鹰嘴骨折。[方法]将尺骨鹰嘴骨折复位，以1枚可吸收螺钉将其与尺骨干固定，尺骨干与螺钉尾部以可吸收线作张力带固定。[结果]可吸收张力带固定尺骨鹰嘴骨折59例，固定牢靠，功能恢复良好。[结论]可吸收张力带固定尺骨鹰嘴骨折操作简便，疗效满意，并发症少，无需2次手术取内置物，值得推广。     

Locking-plate osteosynthesis versus intramedullary nailing for fixation of olecranon fractures: a biomechanical study

Purpose

Intramedullary nailing and locked plating for fixation of olecranon fractures has recently gained popularity. However, these two new technologies have not been compared for their biomechanical efficacy. The aim of this study was to evaluate the biomechanical stability of two newly designed fracture fixation devices for treating olecranon fractures during dynamic continuous loading: the ION intramedullary locking nail and the LCP precontoured locking compression plate.

Methods

Simulated oblique olecranon fractures were created in eight pairs of fresh-frozen cadaver ulnae and stabilised using either the LCP or ION. Specimens were then subjected to continuous dynamic loading (from 25 to 200 N), with a continuous angle alteration between 0° and 90° of flexion, to perform a matched-pairs comparison. Significant differences in the distance between markers surrounding the fracture gap was determined using the Wilcoxon test after four and 300 loading cycles.

Results

The ION resulted in significantly less displacement in the fracture gap at 0° extension (P?=?0.036), 45° flexion (P?=?0.035) and 90° flexion (P?=?0.017) after 300 cycles of continuous loading. The measured displacements were small and were probably not of clinical significance. No mechanical failure or hardware migration was seen with either fixation technique.

Conclusion

This study shows significantly less micromotion for the ION than for the LCP in treating oblique olecranon fractures after 300 cycles of dynamic loading. Both implant types could be appropriate surgical techniques for fixation of selected olecranon fractures and osteotomies.     

Elbow function following tension band fixation of displaced fractures of the olecranon

Fifty-two patients were reviewed following displaced fractures of the olecranon fixed by the tension band technique. Symptoms, range of movement and strength in flexion and extension were assessed, together with the accuracy of reduction. Eighty-five per cent of patients regained very good function. The results confirm that tension band fixation can yield excellent functional results whatever the degree and severity of fracture of the olecranon. The wires must be totally buried to allow full excursion of the triceps tendon.     

张力带固定治疗髌骨横行骨折的研究进展

髌骨骨折中横行骨折最为常见,张力带固定方法,是目前治疗髌骨横行骨折最有效的方法之一。钢丝张力带技术术式简单,使用材料也简单,但不牢固,难以推广;克氏针张力带技术复位好,固定可靠,但容易发生钢丝断裂,克氏针松动的并发症;螺钉张力带技术继承了传统术式操作简单、固定可靠的优点,又克服了克氏针张力带刺激膝周软组织限制早期活动、内固定容易滑脱、断裂等的不足,可以广泛开展。     

Displaced olecranon fractures in children: a biomechanical analysis of fixation methods

BACKGROUND: Wire and suture methods have been used to stabilize pediatric olecranon fractures. This study (1) compared differences in simulated intraoperative compression during fracture reduction, (2) evaluated articular surface compression during cyclic loading of the tension band, and (3) compared fracture stabilization after cyclic physiologic loading at low/high levels. METHODS: Identical olecranon fractures were created in 10 synthetic ulnae and randomized to suture or wire fixation. Compression after fixation and compression during cyclic loading between 10 and 50 N was measured with a load cell at the articular surface and compared with a 1-way analysis of variance (p < 0.05). Twenty-four fractured synthetic ulna were randomly assigned to wire or suture tension band constructs and low- or high-loading groups. The low-load group (12 ulnae) cycled loading from 3 to 10 N for 100 cycles followed by a failure test. The high-load group (12 ulnae) experienced 10 to 100 N before failure testing. Fracture separation (mm) and failure load (N) were compared using a 2-way analysis of variance (p < 0.05). Ten synthetic ulnae were randomized to wire/suture groups and cyclically loaded between 10 to 50 N while measuring loads across the fracture using a load cell. Correlation data were statistically compared with a Fisher transformation and z test (p < 0.05). RESULTS: Residual compression was statistically greater for wire compared with suture. There was no difference in fracture displacement between groups during low loads. Suture had significantly greater displacement compared with wire at high loads. Failure loads were significantly greater for wire at both load settings. Wires transmitted forces across the joint surface more readily than sutures. CONCLUSIONS: Suture tension bands had lower ultimate failure loads and less compression at the fracture site. However, if low loads are expected or if the fracture is reduced easily, the suture tension band may be an appropriate alternative to wire fixation. CLINICAL RELEVANCE: Perhaps, in small children or when using casts in bigger children, a bioabsorbable suture may be used for fracture stabilization avoiding the need for extensive surgery to remove the fixation material.     

Transverse fractures of the olecranon: a biomechanical comparison of three fixation techniques

Introduction  

The gold standard for treating transverse olecranon fractures is tension band fixation. A problem with this technique is migration of the K-wires leading to premature hardware removal. The aim of this study is to compare stability provided by two new techniques designed to eliminate the problem with backing out of K-wires, with that of the recommended tension band technique, performed with a biomechanical in vitro investigation. Our hypothesis was that the two new techniques would provide at least equal stability as the traditional tension band fixation.     

Simple and comminuted displaced olecranon fractures: a clinical comparison between tension band wiring and plate fixation techniques

Introduction

The purpose of this retrospective study is to compare the clinical, functional outcome and complications occurrence between tension band wiring (TBW) and plate fixation both for simple and comminuted displaced olecranon factures.

Materials and methods

Between January 2005 and June 2012 (minimum 1-year follow-up), 78 consecutive patients with Mayo type IIA and IIB fractures were treated with the following methods: tension band wire or plate and screws fixation. The primary outcome of this study was the functional outcome, assessed by the following self-administered evaluation scales: the disabilities of the arm, shoulder and hand, and the Mayo Elbow Performance Score. Secondary outcome measures included the assessment of pain level, analysis of passive range of motion, and the occurrence of any early or late complications.

Results

Comparing the clinical results between the two groups, at mean 33 months follow-up, no significant differences in the functional and clinical outcome were observed. Complications were reported in 48 and 17 % of cases, following TBW and plate fixation in patients treated for type IIA fractures, and similarly in 40 and 23 % of cases in type IIB fractures, respectively. Hardware removal was more frequently performed in TBW group: 38 versus 17 % for type IIA fractures and 20 versus 6 % for type IIB fractures.

Conclusions

The findings of this study indicate that both with the use of TBW and plate fixation excellent/good clinical outcomes with minimal loss of physical capacity, little pain and disability can be obtained in the majority of patients with simple and comminuted displaced olecranon fractures. Hardware removal was most frequently observed after TBW.

Level of evidence

Therapeutic IV.     

The role of cancellous screw with tension band fixation in the treatment of displaced olecranon fractures,a comparative study

Introduction  Fractures of the olecranon are among the most common injuries involving the upper extremity and require operative intervention if displaced. The most commonly used method of fixation for this type of fracture is the AO tension band wiring, although the results of this technique have been generally good, still problems have occurred, including loss of fixation, nonunion, and high re-operation rate for hardware removal. Aim of the study  To compare the results of treatment of displaced fractures of the olecranon using AO tension band wiring versus intramedullary screw with tension band. Materials and methods  In a prospective study, 30 patients with transverse or oblique olecranon fractures, were randomly divided into two equal groups, one group treated using AO tension band wiring the other group using an intramedullary cancellous screw plus tension band. Results  In the screw plus tension band group, 11 (73.3%) patients had excellent results, four (26.7%) had good results and none had fair or poor results, only one(6.6%) patient required second operation for removal of prominent hardware. In the AO tension band group, six (40%) patients had excellent results, five (33.3%) had good, three (20%) had fair and one (6.7%) patient had poor result, and eight patients (53.3%) required second operation for removal of prominent hardware. Conclusion  Using an intramedullary screw combined with tension band in treatment of displaced transverse and oblique olecranon fractures gives better clinical results and has much less re-operation rate for removal of hardware when compared to AO tension band wire fixation, avoiding costs, work time loss and possible complications from hardware removal.     

Surgical technique in tension band wiring method for selected comminuted olecranon fractures

European Journal of Orthopaedic Surgery & Traumatology - The use of tension band wiring (TBW) for comminuted olecranon fractures is less recommendable these days. However, some experts...     

尺骨鹰嘴骨折的张力带效应分析

外伤性尺骨鹰嘴骨折是临床常见的疾病,对此骨折的治疗方法甚多,其中有手法整复、石膏外固定,也有的用单枚螺钉固定,其作用效果不一,且容易引起肘关节活动障碍.我院从1990年7月～1998年12月,应用"张力带克氏针钢丝内固定"治疗35例尺骨鹰嘴骨折,经随访,效果较好,现报道如下.     

Surgical treatment of displaced olecranon fractures by tension band wiring technique

Forty-five displaced olecranon fractures including 14 accompanying dislocated radial heads and seven radial head fractures were treated over a 13-year period by the tension band wiring technique. The use of supplemental internal fixation when necessary allows excellent results with the use of this technique, even in the presence of severe comminution or radial head dislocation. Primary silicone radial head implants fractured in all three patients in which they were used, necessitating repeat surgery in two patients to date. While loss of motion in terminal extension was a common aftermath of displaced olecranon fracture (59%), it was usually minor and functionally insignificant. True Kirschner-wire migration was not a common problem and can probably be eliminated by proper technique. The presence of gaps in the intraarticular surface of the semilunar notch of the ulna produced no ill effects and was compatible with excellent results. If only those cases with isolated olecranon fractures in this series are considered, there were good and excellent results in 29 of 30 cases (97%). Excision of the olecranon fragment(s) should be reserved for those cases when anatomic restoration cannot be achieved with internal fixation.